No-roll-back brake for automobiles



June 28, 1 938. c. A.'MATSON I 2,122,009

NO-ROLL-BACK BRAKE FOR AUTOMOBILES F iled Sept. 14, 1954 5 Sheets-Sheet 1 June 28, 1938.

c.'A. MATS ON .NO-ROLL-BACK BRAKE FOR AUTOMOBILES Filed Sept. 14, 1934 5 Sheets Sheet 2 June 28, 1938. c. A. MATSON NO-ROLL-BACK BRAKE FO R AUTOMOBILES 5 Shets-Sheet 5 Filed Sept. 14, 1834 Jwusrrior we 4 m I Miozyzegy June-28, 1938. c. A. MATSON NO-ROLL-BACK BRAKE .FOR' AUTOMOBILES 5 Shets-Sheet 1 Filed-Sept. 14, 1934 Patented June 28, 1938 I v I Y UNITED STATES PATENT OFFICE NO-ROLL-BACK BRAKE FOR AUTOMOBILES Carl A. Matson, Swampscott, Mass assignor of one-half to John B. Jameson, Concord, N. H.

Application September 14, 1934, Serial No. 744,006

' 1 Claim. (01. 192-4) My present inventionis a novel and improved provided whereby the cramping member is no-rautomatic brake mechanism primarily intended mallymoved with the driving shaft and either for use onautomobiles to prevent an automobile free of engagement of the encircling friction ring from rolling backward when stopped on an inor traveling with the encircling ring, which-ring 5 cline or hill. is itself free to rotate until locked. ,5 l-Ieretofore, various devices have been de- Furthermore, I can hold the mechanism out veloped for preventing reverse movement or rollof engagement when the automobile gears are ingbackward'of automobiles when'stalled on a meshed for driving rearwardly, and I accomgrade or hillwhen the driving clutchis disconplish allthese results automatically. To effect nected, and in my prior development of no-rolla locking action of the cramping ring I provide 10 back brakespI have devised various forms of eithera radially or horizontally actuated crampsuch mechanism, as shown for example in my ing pin, the cramping member being in the form prior Patent No. 1,713,391, issued May 14, 1929, of a flexible spring-like split ring with the cramp- Reissue No. 18,377; Patent No.v 1,713,392, Reing pin or key engaging the abuttingfaces of the issue No. 18,693, and various modifications and split portion. 7 I l5 improvements thereon such as U. S. Patent Nos. This pin or key beingactuated at the initia- 1,886,710, 1,919,474,-and in my various pending tion of the reverse movement of the drivin applications. shaftwill expand the cramping member, actuate I In such prior applications, both of my own dethe same and hold the driving shaft against convelopments and those of other patents, it has tinued reverse movement until released. 20

been customary to utilize'friction rollers or the I I believe that theutilization of a cramping like much in the nature of a Horton clutch, or member, such as I have developed is a distinct somewhat similar friction members; but such novelty in this particular artand I therefore prior devices have not been found satisfactory wish to claimthe same herein broadly.

5 and have involved an expensive and complex con- Further advantages;improvements, and novel 95 struction which-would not function with sufficient details will be hereinafter more fully pointed out speed and accuracy under all conditions. i and claimed. r i

In my present invention I have developed dis- Referring to .the drawings illustrating pre tinctly novel types of devices, eliminated the ferred embodiments of thepresent invention,

rollers, ball-bearings, or the like, and have de- Fig. 1 is a fragmentary diagrammaticview of 30 vised extremely simple, highly. efficient, and inmy no-roll-backunit applied between the drive stantly active clutching instrumentalities which shaft and the universal joint in the usual type are peculiarly efficacious in a no-roll-back brake of automobile construction; I I or clutch for automobiles. v Fig. 2 is an enlarged cross-sectional viewshow- In carrying outmy present invention I have ing the cramping and brakingvaction preventing 35 developed a cramping member normally enreverse rotation; tirely free and out of engagement with the 00- Fig. 3 is a fragmentary view illustrating reoperating devices while the driving shaft is in verse movement of. the shaft with the locking rotation, but instantly operable on a reverse members out of position while the car, is being 4 movement such as is imparted to the shaft when driven rearwardly; g I 40 a car would tend to back down a'hill or grade Fig. 4 is an enlarged plan view of thelocking when the clutch is released or when stalled. My and releasing operating devices; novel cramping member can be quickly installed Fig. 5 is a fragmentary horizontal view of the on existing automobiles; is entirely free of accimeans for normally carrying the cramping mem dentallycatching, and its operation and funcber i n forward rotation with the shaft;

tion is insured under all conditions. The brak- Fig. 6 is a vertical cross-sectional view in noring operation is positive and practically instanmal position during the forward rotation'of the taneous while the construction is wear-resisting, vehicle; Y or if any wear occurs, it isautomatically com- Fig. '7 is a right-angled cross sectional view of pensated by the normal operation of the devices. the mechanism as shown in Fig. 6; 50

In carrying out my invention ,1 apply a flex-5 Fig. 8 is a vertical cross-sectional view showing iblecrampingmember around'the normally mova modified form of cramping member; f ing driving shaft of an. automobile, or other drive Fig. 9 is a vertical cross-sectional view-of th member, and I provide a frictio'n'ring or surface modification of Fig. 8; I

encircling. the cramping member. Means are Fig. 10 is a plan view of the cramping member; 55

Fig. 11 is a cross-sectional view of a modified form showing a horizontally positioned key to actuate the braking member;

Fig. 12 is a fragmentary cross-sectional View on the line IZI2 of Fig. 11;

Fig. 13 is a fragmentary cross-sectional view showing the brake released;

Fig. 14 is an enlarged cross-sectional fragmentary view illustrating the operation of the operating key.

Fig. 15 is a cross-sectional view on the line l5-i5 of Fig. 11;

Fig. 16 is a fragmentary cross-sectional plan view of the modified form of Fig. 11;

Fig. 17 is a view in perspective of the three rings, and

Fig. 18 is a fragmentary diagrammatic view of the unit and brake pedal operating means.

As shown in the drawings, l designates gen' erally the exterior of an automobile transmission gear case, 2 designating the usual hand gear shift lever, and 3 the foot brake. The position of this gear case in standard automobile construction is at the rear of the engine, and imparts variable speed to the propeller shaft 5, through the connections with the universal joint 6.

It is customary to attach to the engine driving shaft between the gear box I. and the universal joint 6 a gear from which the speedometer of an automobile is driven, and it is one of the important advantages of my present invention to attach the no-roll-back unit at this point, which feature is described and claimed broadly in my copending application Serial No. 750,838 filed October 31, 1934. The operating portions of my unit are enclosed within a casing it, readily attached to and substituted for the speedometer driving gear casing, my entire unit being compact and contained within the space provided and from which the speedometer drive leads through a flexible shaft, as shown at I2.

The no-roll-back unit construction as shown in the preferred forms of Figs. 2, 3, and 6 will now be described. The drive shaft l5 of the engine carries a hub l6 keyed at I! thereto and in constant rotation therewith. This hub has a notch l8 to receive one end of a key 20, said notch being formed slightly larger than the size of the key 23 which projects into said notch and with a rounded portion in one edge of the notch, as shown at 2!, to permit tilting or cramping of the key 28, as will be explained. Surrounding the hub I6 is a braking member 22 in the form of a split ring with the abutting ends 23 and 2t normally spaced a distance slightly greater than the width of the key 20 which is fitted therein. 'Encircling the member 22 is a solid locking ring or brake 25, having a series of notches 26 in its outer periphery which are engaged by the head 28 of a pawl 30, said pawl being mounted on a pin 3| secured to the casing. Preferably the head 28 has a bevelled face' 29, and each of the notches 26 has at one end a similar bevelled face 32 corresponding tolthe bevel 29 on the head of the pawl 30.

The pawl 30 is held in locked position, as shown in Figs. 2 and 6, by a locking prong 33 having a shouldered portion 34 fitting onto a correspondingly formed part 39 in the head of the pawl 30, the locking prong 33 being freely mounted on a stud 35 secured to the casing I0. Bearing against the locking prong 33 is a spring:

pressed plunger 35 which is adapted to slide within a socket 3'! in the extension 38 on the casing It, with a coiled spring 48 bearing between the head of the plunger 36, which is preferably recessed to receive the same, as shown in Figs.

2, 3, and 6 and against the face of an adjustable screw 4!, which is threaded into the extension 38 and serves to afford an adjustment of tension of said spring 40.

This spring-pressed plunger 36 normally tends to hold the locking prong 33 to force the pawl 38, with the head 28, into locking engagement with any one of the notches 26 which may be in position to receive the same. Preferably I form the member 22 with a pair of depending lugs 43 and to adjacent the abutting faces 23 and 24. The lug 33 has a bevelled or cut-away portion 55 substantially equivalent in extent to the bevelled face 25 on the hub It to facilitate the looking and, hence, binding action of the key 20. Also, I preferably form the lug 43 in the face 241, with a shoulder 46 to act as a bearing for the projection 47 on the key 25.

During the normal rotation of the driving shaft l5, as shown in the direction of the arrow 50, Fig. 6, the key 20 abutting between the faces 23 and 2d of the distortable or cramping brake member 22 will carry the same free of contact with the locking ring 25, which ring is held in fixed position by the pawl 30, the locking prong 33,-and the spring-pressed plunger 36.

However, upon initiation of reverse movement of the shaft l5, as shown in the direction of the arrow 5!, Fig. 2, the key 20 will spread the member 22, distorting the same sufficiently to contact against the inner face of the locking ring 25, thereby holding the same against reverse movement. The bevelled faces 21 and 45 facilitate this action of the key 28, as well as affording bearing surfaces for the key 20 during this operation.

With the key 20 thus acting to expand and distort the member 22, the whole mechanism is locked against reverse rotation and the parts are in position, as shown in Fig. 2. In order to re lease the locking action, I form on the end of the shifting levers which operate the gears in the gear box l bevelled faces suitably positioned to cooperate to release the locking action. 55 designates the usual gear shifting rod actuated by the gear shifting lever 2, which reciprocates in the direction of the arrow 56, this rod being that for the first forward speed. Hence, as the gear shift lever 2 is moved, the rod 55 is reciprocated and is'provided with a bevelled face 56 adapted to cooperate with a corresponding bevelled face 57 on the locking prong 33. This moves the looking prong against the tension of the spring 40 and releases the pawl 30 by swinging the lower portion 34 out of engagement with the head 28 and into the cut-out part 59 in said pawl 30, raising the pawl 30 by contact with the face 50 of the pawl, as clearly shown in Fig. 3, thereby freeing the locking ring 25, releasing the brake action between the ring and member 22 and restoring these parts to normal position, with the key 23 in substantially radial position, as shown in Figs. 3 and 6.

In order to hold the locking pawl 30 and prong 33 in inoperative position as shown in Fig. 3 during the rear driving or pushing of the automobile rearwardly, I provide a pivoted rod 65 mounted on a pin 66, secured to the casing Ill, and of. suitable length to have its extreme end 61 bear against the face 68 of the locking prong 33 when the gear shifting rod 55 is moved into reverse position. see Fi 3. Thus. the automobile may be=either drivenrearwardly' or so moved byh'and-fas irr garage, or thelike; with the lockingun-it held out of 'operation against reverse or rear rolling" brakingaction, this actionbeing. entirely automatic when thegearshifting lever-2 is moved to connect the transmission gearing into rear driving operation.-

- To prevent thelock'ing pin 65 from its action;

duringthe'forwardEdriving operation when the car is in second and high speeds, I form the-shift rod "In -with a recessed I part" II so positioned that the "locking' pin" 65-willb'e held upwardly out of contact'with the locking prong 33; permitting the same to be pressed forwardlywith the springpressed plunger36' and, hence; held in the normal position as shown in'= Fig. 2.

To'facilitatethe spreadingaction' ofthe cramp- I ing "member 22', -Ipreferably form the same with one "or' more "kerfs-H' -M preferably at each side of e2 frictionplunger-I5, see Figs. 2 and 6. This facilitates the springing action ofthe member 22 .when thegkey ZIIiscperatedto spread the split faces'23 and 24 -andprevents the member 22"from splitting.- Preferably I arrange a plurality of I these'plungers'l5 -l5i' three being herein shown,

in the form of' spring-pressed plungers each arranged in the sockets 'lli formed inthe member face of: the edging of the ring 25 to facilitate the assembly of-the member 22 withthe plungers I5 therein as it is sliding into position, the bevelled faces 18 thus automatically compressing the spring-pressed plungers '15' until they are in con- --tact with the inner surface of the ring 25, as

will 1 be appreciated.

Ialso prefer to form*a pluralityof oil carrying grooves 80 intheouter face-ofthe member 22- which -still'further acts to prevent the opposite parts. of the member 22 from slipping in action,

' as well as providing at all times means to carry the lubrication around the surfaces when desired. As shown in Fig. 5, I may form a recess 8I in the side of the member 22 and apply a roll or stud 182 of less diameter than the recess 8| secured on,

a stem 83 to the member I6I which will function to carry the members 22 and 25 together'when in non-breaking operation by reason of the lost motion between the roll 82 and recess 8I. It will be noted that I apply my entire unit to the end portion of the drive shaft I5 without disturbing the usual ball bearings 85 and speedometer drive unit 86, which is connected with a flexible shaft I2, as previously explained, my unit being sufliciently compact to be contained within the casing I applied between the transmission I and universal joint structure 6, being enclosed in an oil-tight cover 91 and a flexible washer I98 by a headed bolt I 00 threaded on the end of theshaft I with suitable packing 98, as is usual, completing the oil-tight construction. A Washer I6I be-- tween the speedometer gear 86 and the member '22 and ring 25 is also provided.

are preferably formed a'sa series of wave-like contourswitli the top-portions III-I of l substantial extent to act as the-contactmembers between the: cramping-member" I05 'and the inner surface of the ring25 when the key 20 expands anddistorts the -member- I 05 into braking "position.

The important object of the wave-like" or grooved structure is to facilitate the operation of my brakevmechanism when the oil or grease in which the -unit is -packedis 'cold and, hence, to have -the mechanism readily operative at starting as' wel-l as after the oil and grease-is warmed up and inlidhidconditibn during thexrunning of the engine.

Preferably,- also, I' form the spring-presse plungers 'll'f in staggered relation so that these members "I5 will not 'tend to form on the-groove in the innerfaceof the ring 25 but, on I the contraryj willcover'the-entire width ofthe surface ofsaid'ring-fwillaidin keeping'the oil or grease scraped fr'e'e therefrom; and will each have its own bear'ing line, thus distributingthe friction andstrainthroughoutthe width of the member 22-andring 25i Referringto the modified form shown in Figs. 11; 12; 13; and" 14; If have-herein illustrated a fQrm' Wherein-I utilize a horizontal key to distort or'spring thecra-mping member to eifect'the lock ingaction': In-this-form, also, I preferably em ploy a three-ringstructure, whereas in the former form's' heretofore"described, I utilize'two only.

Referringto-the modificationof Figs; llt o 18;

I key't'o m emberIB-within the casing IIla ring IIIlat I I I: :Surrounding the ring III] is the distortable member -'I I2-having opposed .faces II6 and I'I'I 'imc'ontact with the horizontal key I20,

which-actstospread the cramping'member H2 and lock the mechanism against reverse movement: 'Normally'the mem'ber- I I2 is keptfrom rotation in-the present form by'a stud I2I' held on-anarm I22Ewhich arm 'is pivoted at I23 and extends "around *thestud I 65 carrying the pivoted rod65I-"' surroundinggthe' cramping-member II2 isa secondjringfl25*which; preferably, is in the form of a split ring structure, as shown in Fig. 11. The split ring I 25 is provided with a notch in which the element IIlI is adapted tofit, as shown dered portion I33 in position to engage that portion of the horizontal key I20 which projects beyond the width of the cramping member II2, as shown in Figs. 12 and 14. When the beveled end face of the rod 55 strikes the facing I3I of the locking pawl I30, the same is raised and the rod 65 will drop intoposition to hold the locking lever I30, as shown in Fig. 13, and thus normally out of position, causing the mechanism to be inoperative-such as during backing or reverse movement of the car. Upontheshifting of the gears to forward speed, however, the rod 65 is raised by its contact with the bevelled faces on the shifting rod 55 or III, and the locking pawl I drops, by its own weight, into position withthe arm I34 in alignment with the projecting end of the horizontal cramping key I20, as shown in Figs. 11 and. 12. While the vehicle is being driven ahead or in the direction of the arrow I35, viewed in Figs. 11 to 14, there is no clamping action; but the instant a reverse-movement is effected, the

key I20 is twisted or cramped by the lever I30, spreading the member H2 and distorting it sufliciently to effect a braking action and to hold the shaft I5 and connected portions against reverse movement.

In the modified form as above explained wherein three ring-like members are provided, with the intermediate ring-like member for the distortable braking action, I provide a separate attachment to efiect release of the same. For this purpose the arm I22 has a rearward extension with an enlarged opening I40 to fit over the stud 06, said opening permitting a limited amount of oscillation on the pivot I23. The arm I22 is also provided with a recess I H in which a pawl member I44 projects from a shaft I45, said shaft being mounted in suitable bearings I46 in the easing I and extending outside the same, to which outer portion a lever I41 is secured by a set screw A spring I48 normally holds said arm I41 upwardly with a pawl actuating the lever I22 to move the pin I2I to the right, viewed in Fig. 11, under a slight yielding tension. This action tends to hold the member H2 in desired position and against the line of rotation of the shaft l5 and the shaft H0. Secured to the lower part of the arm Ml is a spring I50 with its other end at tached to the brake lever 3. Hence upon the operator applying pressure to the brake lever 3, the shaft I45 which is mounted in a suitable bearing in the frame I0 at the side, as best shown in Figs. 11 and 18, is rocked relieving the tension of the spring I48, thus exerting considerable rocking action on the lever I22 moving it on its pivot I23 to the limit allowed by the enlarged opening M0 on the stud 66 and positively but yieldingly imparting a movement of the member II2 against the rotation of the shaft I5 and associated parts, thus also closing the space or gap normally between the ends of the member H2 and the cramping key I20, moving the key directly into contact with the locking pawl I30; thereupon instantly permitting the locking pawl to take efiect on the key I20, and thus apply the braking action by expanding the member II2. These members I I0, I I2, and I25 are all enveloped by a flanged ring I32 which will hold them in assembled position. This flange ring I32 is adapted to fit within a shouldered recess formed in the interior of the casing I0, as shown in Fig. 12: A set screw I55 is threaded thru a tapped recess in the side of the casing to engage a notch I56 in the ring I32 to hold the same in adjusted position.

By this means I prevent any substantial rearward movement of the automotive vehicle before the no-roll-back brake takes effect, thereby securing substantially instant braking action.

While this method just described is not automatic and, therefore, not as desirable in many cases as the two-ring structure of the first described figures and operation, yet it is extremely simple in construction and operation and a very economical unit to build, assemble and install.

In both forms of my present no-roll-back structure, an extremely simple and compact unit is provided and one wherein I can utilize to the fullest extent the advantages of my novel arrangement wherein I connect the entire no-rollback structure on the drive shaft by simply removing the speedometer driving gear, or a part of same, assembling my unit thereto and cramping the same with its entire casing thereon. I have described and claimed this feature broadly in my copending application Serial No. 750,838, filed October 31, 1934.

I claim:

In a no-roll-back brake of the kind described, a driving shaft, a cramping member partly encircling said drive shaft, means encircling said cramping member and adapted to be clutched by the distortion of said cramping member to hold the shaft against reverse rotation, and means providing a'preliminary friction engagement between said eramping member and said encircling means in combination with an operating key contacting on the ends of said member.

CARL A. MATSON. 

